Until recently, most patients requiring tube feedings were fed by plastic or rubber, large-bore nasogastric tubes. Unfortunately, when used for a prolonged period, these tubes irritate the nasopharynx, esophagus, and stomach. During the 1970's, soft, small-bore feeding tubes were made of polyurethane or silicone because they could be placed through the nares into the stomach or upper small intestine with minimal discomfort to the patient. Although the incidence of mechanical irritation to nares, stomach, and duodenum has been greatly reduced by the newer tubes, there still remain problems associated with their use. Such problems include the ease of dislocating the feeding tube, particularly during coughing or vomiting. Additionally, accidental upward displacement of the tip of the tube from its original intended position (either in the stomach or the intestine) can place the patient at risk.
Conventional feeding tubes have been made of very hard plastic or hard rubber hoses so that they can be inserted into the stomach to support nutrition. Stiff needle-like objects, called stylettes were often used to lend rigidity to the tube to facilitate its placement. After insertion of the feeding tube, the stylette would then be removed. However, the stylette would sometimes come out of the tube, puncture, and injure the patient.
Other approaches involve the use of a weighted tube which has a bolus of mercury or tungsten attached at the distal tip. This approach, however, brings with it the risk of causing trauma to the infant because the tip must pass between very delicate tissues in the nasal cavity and in the esophagus. As a result, internal bleeding may follow which may lead to enterocolitis, which is infection and inflammation of the feeding tract. Even tubes with heavy mercury weights can be relocated during bouts of severe abdominal coughing.
U.S. Pat. No. 4,778,455 discloses combining a metal material within synthetic resin tip material to provide a weighted tip without the risk of trauma associated with a bolus of metal. However, the composite resulting from this combination is less elastic than the initial synthetic resin and less acceptable.
Pliable small-bore tubes may be inserted under fluoroscopy by a radiologist, or may be inserted by nurses or physicians. However, the need arises to ensure proper positioning of such tubes before feedings are initiated. At present, no consistently reliable method other than radiography can confirm the placement of these tubes. Accordingly, there has arisen a need for position-indicating indicia to enable the determination and monitoring of tube placement.
Against this background, the need has arisen to manufacture and distribute an infant feeding tube, the position of which can easily be determined, which is stiff enough to insert, but without having a stylette inside. Ideally, the stiffer the better, for ease of insertion. Additionally, with the high costs of medical care, there has arisen a need for an infant feeding tube which is inexpensive, can be used once, and then thrown away.